linux-kernel - Re: [RFC 0/1] BPF tracing for arm64 using fprobe

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:   Mon, 21 Nov 2022 23:40:23 +0900
From:   Masami Hiramatsu (Google) <mhiramat@...nel.org>
To:     Peter Zijlstra <peterz@...radead.org>
Cc:     Steven Rostedt <rostedt@...dmis.org>, Chris Mason <clm@...a.com>,
        Mark Rutland <mark.rutland@....com>,
        Alexei Starovoitov <alexei.starovoitov@...il.com>,
        Florent Revest <revest@...omium.org>,
        bpf <bpf@...r.kernel.org>, Alexei Starovoitov <ast@...nel.org>,
        Daniel Borkmann <daniel@...earbox.net>,
        Andrii Nakryiko <andrii@...nel.org>,
        KP Singh <kpsingh@...nel.org>,
        Brendan Jackman <jackmanb@...gle.com>, markowsky@...gle.com,
        Masami Hiramatsu <mhiramat@...nel.org>,
        Xu Kuohai <xukuohai@...wei.com>,
        LKML <linux-kernel@...r.kernel.org>,
        Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        Linus Torvalds <torvalds@...ux-foundation.org>,
        Christoph Hellwig <hch@...radead.org>
Subject: Re: [RFC 0/1] BPF tracing for arm64 using fprobe

On Mon, 21 Nov 2022 11:09:21 +0100
Peter Zijlstra <peterz@...radead.org> wrote:

> On Fri, Nov 18, 2022 at 01:06:08PM -0500, Steven Rostedt wrote:
> > How do I know that a function return was modified by BPF? If I'm debugging
> > something, is it obvious to the developer that is debugging an issue
> > (perhaps unaware of what BPF programs are loaded on the users machine),
> > that the return of a function was tweaked by BPF and that could be the
> > source of the bug?
> 
> Have it taint the kernel if something is overridden ;-) Then we can all
> ignore the report until it comes back without taint.

Hmm, indeed. BTW, error injection should set that too.

Thanks,

-- 
Masami Hiramatsu (Google) <mhiramat@...nel.org>